libssh up to 0.7.5/0.8.3 SSH2_MSG_USERAUTH_SUCCESS Message improper authentication

CVSS Meta Temp Score
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CTI Interest Score
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8.4$0-$5k0.00

Summaryinfo

A vulnerability identified as very critical has been detected in libssh up to 0.7.5/0.8.3. This impacts an unknown function of the component SSH2_MSG_USERAUTH_SUCCESS Message Handler. This manipulation causes improper authentication. This vulnerability is registered as CVE-2018-10933. Remote exploitation of the attack is possible. Furthermore, an exploit is available. This vulnerability is historically significant due to its background and the way it was received. You should upgrade the affected component.

Detailsinfo

A vulnerability has been found in libssh up to 0.7.5/0.8.3 and classified as very critical. Affected by this vulnerability is some unknown functionality of the component SSH2_MSG_USERAUTH_SUCCESS Message Handler. The manipulation with an unknown input leads to a improper authentication vulnerability. The CWE definition for the vulnerability is CWE-287. When an actor claims to have a given identity, the product does not prove or insufficiently proves that the claim is correct. As an impact it is known to affect confidentiality, integrity, and availability. The summary by CVE is:

A vulnerability was found in libssh s server-side state machine before versions 0.7.6 and 0.8.4. A malicious client could create channels without first performing authentication, resulting in unauthorized access.

The bug was discovered 10/16/2018. The weakness was published 10/16/2018 by Peter Winter-Smith with NCC Group as libssh 0.8.4 and 0.7.6 security and bugfix release as confirmed advisory (Website). The advisory is shared at libssh.org. The public release has been coordinated with the project team. This vulnerability is known as CVE-2018-10933 since 05/09/2018. The attack can be launched remotely. The exploitation doesn't need any form of authentication. Technical details are unknown but a public exploit is available. The price for an exploit might be around USD $0-$5k at the moment (estimation calculated on 06/21/2024). Due to its background and reception, this vulnerability has a historic impact. The advisory points out:

libssh versions 0.6 and above have an authentication bypass vulnerability in the server code. By presenting the server an SSH2_MSG_USERAUTH_SUCCESS message in place of the SSH2_MSG_USERAUTH_REQUEST message which the server would expect to initiate authentication, the attacker could successfully authentciate without any credentials.

It is possible to download the exploit at exploit-db.com. It is declared as highly functional. We expect the 0-day to have been worth approximately $25k-$100k. The vulnerability scanner Nessus provides a plugin with the ID 118180 (Debian DSA-4322-1 : libssh - security update), which helps to determine the existence of the flaw in a target environment. It is assigned to the family Debian Local Security Checks and running in the context l. The commercial vulnerability scanner Qualys is able to test this issue with plugin 171823 (OpenSUSE Security Update for libssh (openSUSE-SU-2018:3200-1)).

Upgrading to version 0.7.6 or 0.8.4 eliminates this vulnerability. The upgrade is hosted for download at libssh.org. A possible mitigation has been published immediately after the disclosure of the vulnerability.

The vulnerability is also documented in the databases at Exploit-DB (45638), Tenable (118180) and SecurityFocus (BID 105677†). Additional details are provided at twitter.com. Similar entry is available at VDB-129621. If you want to get the best quality for vulnerability data then you always have to consider VulDB.

Productinfo

Name

Version

CPE 2.3info

CPE 2.2info

CVSSv4info

VulDB Vector: 🔍
VulDB Reliability: 🔍

CVSSv3info

VulDB Meta Base Score: 8.5
VulDB Meta Temp Score: 8.4

VulDB Base Score: 7.3
VulDB Temp Score: 7.0
VulDB Vector: 🔍
VulDB Reliability: 🔍

NVD Base Score: 9.1
NVD Vector: 🔍

CNA Base Score: 9.1
CNA Vector (Red Hat, Inc.): 🔍

CVSSv2info

AVACAuCIA
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VectorComplexityAuthenticationConfidentialityIntegrityAvailability
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VulDB Base Score: 🔍
VulDB Temp Score: 🔍
VulDB Reliability: 🔍

NVD Base Score: 🔍

Exploitinginfo

Class: Improper authentication
CWE: CWE-287
CAPEC: 🔍
ATT&CK: 🔍

Physical: No
Local: No
Remote: Yes

Availability: 🔍
Access: Public
Status: Highly functional
Download: 🔍

EPSS Score: 🔍
EPSS Percentile: 🔍

Price Prediction: 🔍
Current Price Estimation: 🔍

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Nessus ID: 118180
Nessus Name: Debian DSA-4322-1 : libssh - security update
Nessus File: 🔍
Nessus Risk: 🔍
Nessus Family: 🔍
Nessus Context: 🔍

Saint ID: libssh_auth_bypass
Saint Name: libssh authentication bypass

Qualys ID: 🔍
Qualys Name: 🔍

MetaSploit ID: libssh_auth_bypass.rb
MetaSploit Name: libssh Authentication Bypass Scanner
MetaSploit File: 🔍

Exploit-DB: 🔍

Threat Intelligenceinfo

Interest: 🔍
Active Actors: 🔍
Active APT Groups: 🔍

Countermeasuresinfo

Recommended: Upgrade
Status: 🔍

Reaction Time: 🔍
0-Day Time: 🔍
Exposure Time: 🔍

Upgrade: libssh 0.7.6/0.8.4
Suricata ID: 2026526
Suricata Class: 🔍
Suricata Message: 🔍

Timelineinfo

05/09/2018 🔍
10/16/2018 +159 days 🔍
10/16/2018 +0 days 🔍
10/16/2018 +0 days 🔍
10/16/2018 +0 days 🔍
10/17/2018 +1 days 🔍
10/17/2018 +0 days 🔍
10/18/2018 +1 days 🔍
06/21/2024 +2073 days 🔍

Sourcesinfo

Advisory: libssh 0.8.4 and 0.7.6 security and bugfix release
Researcher: Peter Winter-Smith
Organization: NCC Group
Status: Confirmed
Confirmation: 🔍
Coordinated: 🔍

CVE: CVE-2018-10933 (🔍)
GCVE (CVE): GCVE-0-2018-10933
GCVE (VulDB): GCVE-100-125365

OVAL: 🔍

SecurityFocus: 105677 - Libssh CVE-2018-10933 Authentication Bypass Vulnerability

scip Labs: https://www.scip.ch/en/?labs.20161013
Misc.: 🔍
See also: 🔍

Entryinfo

Created: 10/17/2018 07:04
Updated: 06/21/2024 19:04
Changes: 10/17/2018 07:04 (93), 04/05/2020 15:04 (8), 05/25/2023 15:18 (14), 06/21/2024 19:04 (14)
Complete: 🔍
Cache ID: 216::103

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